The present invention relates to pumps driven by brushless electric motors. More particularly, the invention relates to impeller pumps driven by generally flat structured, brushless electric motors.
Brushless electric motors have been suggested and/or used for various purposes. In general, such motors come in at least two configurations; a drum style motor in which the rotor and stator of the motor have generally cylindrical shapes; and a flat style motor in which the rotor and stator of the motor are present as generally flat discs. Although the drum style motors are often capable of generating more power, the flat style motors have the advantage of being compact in size.
Flat style brushless electric motors have been suggested for use with impeller pumps. See, for example, Mizobuchi et al U.S. Pat. No. 4,806,080; Kricker et al U.S. Pat. No. 5,332,374; and Atsumi U.S. Pat. No. 5,407,331. There continues to be a need to provide new impeller pumps driven by flat style brushless electric pumps, in particular for pumping liquids, such as water and the like.